Control means for air circulating systems



Dec. 10, N A S 2,224,407 CONTROL MEANS FOR AIR CIRGULATINQ SYSTEMS Filed Feb. 15, 1958 J6 ,i 15 J I l V IL 17 17 2i 1: a n n u m Z2 MWMW i S Q A, 8

N, Z5 QQ INVENTOR, Zv-ww BY A TTORNEYS.

Patented Dec. 10, 1940 Q A 2,224,407

UNITED- STATES PATENT OFFICE CONTROL MEANS FOR AIR. CIRCULATING SYSTEMS Norman Passur, Oakland, Calif.

Application February 15, 1938, Serial No. 190,622

3 Claims. (Cl. 98-39) This invention relates to air circulating sysand mixed with the interior air. Washing and tem of the type used in the heating, cooling, and filtering means may beincluded in the system at air conditioning of buildings, vehicles, and other suitable points, but such means being well known inclosed spaces. in the art, have been omitted from the drawing.

The principal object of the invention is to pro- A radiator or absorber, which may be used either 4 vide means for automatically controlling the relfor heatlng or cooling the air, is represented ative amounts of air taken in and mixed from at l0. two sources, according to the temperature of A system of the type described above will not one source, in order to prevent overloading the operate successfully or economically when the 10 heating or cooling functionsof the system. A outside atmospheric temperature is subject to second object is to provide automatic control wide variations between extremes of heat and means which will operate in response to both cold. If the areas of the outside and inside air high and low temperatures. A third object is inlets 3 and 5 are so designed as to supply fresh to provide an automatic means which will con;- and recirculated air in fixed proportions, the 16 trol the amount of power used in moving the air, amount of fresh air, even though it be the miniin order to prevent waste thereof. Still furmum necessary for proper ventilation, is so great ther objects and advantages of the invention will as to require excessive capacity in the cooling be apparent from the following specification, and heating apparatus when the outside temperwhich should be read with the understanding that ature rises above ,or falls below a middle or modchanges, within the limits of the claims hereto crate range, say for example between 75? F. and appended, may be made in the form, construc- 40 F. tion and arrangement of the various parts, with- The present invention meets this difliculty by out departing from the spirit of the invention. providing an excess of outside air during such The invention is particularly useful in connectimes as the outside temperature is within a mod- 25 tion with air conditioning systems in railway and crate range, say between 75 F. and 40 F., so that other vehicles, although it is in no sense limited during such times the air in the car or room isv thereto,'and may be used with equally good refreshened to a greater extent than necessary, suits in heating, cooling or ventilating systems in and then increasing the proportion of recirculated buildings or other inclosed spaces. air when the outside temperature exceeds these The accompanying drawing is a diagram'iiiuslimits, so that less cooling or heating capacity is trating the functional relations between the slew required. This system is especially useful in raileral elements of the invention. The positional way and other vehicles, where both space and relation of said elements as shown is for illusavailable cooling and heating power are limited, tration only, and is not material to the invenand where due to mobility, extremes of temperation. ture do not persist for any great length of time. 35

Referring to the drawing, the reference nu- The proportioning of the air supply, as between meral I designates the interior of an inclosed outside fresh air and recirculated inside air is space, such as a railway car or a room in a accomplished, automatically, in the following building, having walls 2. 3 is a fresh air inlet manner. The inside air inlet 5 is provided with opening in one of said walls for admitting air a shutter ll, shown in the diagram as composed 4 from the outside atmosphere into an inclosed of a plurality of movable vanes, which shutter mixing chamber 4. 5 is an air inlet opening for is opened and closed by a rod l2 operated by a admitting air to said mixing chamber 4 from solenoid l3. It is assumed that the weight of the the interior of the vehicle or room I. 6 is a rod [2 closes the shutter II when the solenoid fan for circulating the air, said fan sucking the I3. is not energized, and that said solenoid, when air in through either or both inlets 3 and 5 and energized by current supplied from a source ll discharging it at 1 into the interior of the car through wires I5, opens the shutter. or room. 8 is a separate booster fan driven by Two thermostatic switches ii are positioned an electric motor 9, which operates only on the in the fresh air inlet 3, where they are affected I air entering through the outside inlet 3. by the temperature of the outside atmosphere. u The parts described above are common and The contacts ll of said thermostats are connected well known, and cooperate to form the usual air, a in parallel by wires l8, and are included in series circulating system by which the air in an inclosed in the circuit of the solenoid it. Therefore when space is caused to circulate and be ireshened by the contacts ll of either thermostat are closed, outside air drawn in more or less continuously the solenoid i8 is energized and the shutter ll is opened. One of the thermostats I6 is set to close its contacts when the temperature of the atmosphere rises above a predetermined maximum, say 75 F. and the other thermostat is. set

, I l remains closed and all the air is supplied from outside through the inlet 3.

A manually controlled shutter l9, operated by a rod 20 having'a handle 2|, is provided in the fresh air inlet 3 for closing the same when necessary, as for example when a railway car is passing through a tunnel and outside air must be temporarily excluded. The rod,20 of the shutter I9 operates a pair of contacts 22 connected with the wires l8 in parallel with the thermostat contacts I], so that the recirculated air shutter I I is automatically opened whenever the manual fresh air shutter I9 is closed.

A magnetic relay 23 is included in the circuit of the solenoid l3, and the contacts 24 of said relay control the motor 9 of the fresh air booster fan 8, said motor being operated by current supplied by wires 25. The relay 23 is so arranged that its contacts 24 are open when the solenoid circuit is energized, so that the booster fan I operates only when the recirculated air shutter II is closed and all the air is being supplied through the fresh air inlet 3. When the recirculated air shutter II is open, or when the manually operated fresh air shutter I9 is closed, the booster fan 8 is idle. This not only economizes on power, but also reduces the amount of fresh air drawn in when the recirculated air inlet is open. The respective inlets 3 and 5 are so proportioned that, when the fan I is idle, the

amount of fresh air drawn in through inlet 2 is not enough to overload the cooling or heating capacity of the coil I O.

I claim:

1. In an air circulating system having an inlet for fresh air and an inlet for recirculated air, a movable shutter for said recirculated air inlet, electromagnetic means for operating said shutter, a thermostatic switch responsive to the temperature of the air outside said fresh air inlet for controlling said electromagnetic operating means, a separately movable shutter for said fresh air inlet, and a switch connected with said freshair shutter and operated by the movement thereof for controlling the operating means of said recirculated air shutter.

2. In an air circulating system having an inlet for fresh air and an inlet for recirculated air, an electric fan in one of said inlets, a movable shutter for said recirculated air inlet, electromagnetic means for operating said shutter, a thermostatic switch responsive to the temperature of the air outside said fresh air inlet for controlling said electromagnetic operating means and said fan, a separately movable shutter for said fresh air inlet, and a switch connected with said fresh air shutter and operated by the movement thereof for controlling said fan and the operating means of said recirculated air shutter.

3. In an air circulating system having an inlet'for fresh air and an inlet for recirculated air, a movable shutter for said recirculated air inlet, means for operating said shutter, means responsive to the temperature of the air outside said fresh air inlet for controlling said shutter operating means, a separately movable shutter for said fresh air inlet, and means connected with said fresh air shutter and operated by the movement thereof for controlling the operating means of said recirculated air shutter.

NORMAN PASSUR. 

